Solution
= Solution
<Commutativity> of the element <binary operation> does not remove the ordering of a <list comprehension>. For ordinary addition, take `xs = [1,2]` and `ys = [10,20]`. Then
$$
[1,2]\,X_+\,[10,20]=[11,21,12,22],\qquad
[10,20]\,X_+\,[1,2]=[11,12,21,22].
$$
The middle entries occur in opposite orders. Hence
$$
\boxed{\text{False: the lifted operation need not be commutative.}}
$$